Organic Dyes Containing Coplanar Dihexyl-Substituted Dithienosilole Groups for Efficient Dye-Sensitised Solar Cells

Figure 4

(a) ATR-FTIR spectrum of CL1 dye showing sharp phenyl and thiophene ring modes at 1517, 1491, 1375, and 1256 cm⁻¹, whilst the C–N stretching mode of triarylamine appeared at 1348 cm⁻¹. (b) ATR-FTIR spectrum of CL1 dye adsorbed on TiO₂ showing the υ_asym(COO⁻) and υ_sym(COO⁻) stretching modes of carboxylate linker groups at 1590 and 1382 cm⁻¹, respectively, whilst the C≡N stretch frequency was unchanged at 2209 cm⁻¹.

(a)

(b)